Although squeeze bottle types sprayers have been used for many years, such sprayers were largely replaced for a long period of time by pressurized can dispensing systems. One squeeze bottle dispenser which has come into use as a substitute for pressurized cans is described in U.S. Pat. Nos. 5,183,186 and 5,318,205. These patents show a squeeze bottle dispenser in which an air passageway and a product (i.e., fluent material) passageway meet in a tapered mixing chamber. In the device of that invention, the tapering of the mixing chamber direct the air flow at an angle to the flow of liquid, resulting in turbulence in the liquid in the mixing chamber. This turbulence breaks the liquid up and intimately mixes it with the air. As a result, a fine spray is propelled out of the orifice.
One characteristic of current dispensers such as those described in U.S. Pat. Nos. 5,183,186 and 5,318,205 is that the amount and density of the spray is fixed. In other words, current dispensers only provide for either an open position, in which a fixed density spray is made or a closed position in which there is no spray.